Diagsheet

2020 Chevrolet Blazer · symptom sheet

Engine overheats or leaks coolant

  • 47owner reports
  • 55,000median miles
  • $1,400median quote
  • 0involved a crash

Newest report Jul 10, 2026 · checked Sep 19, 2026

70 of the 213 complaints on this car are about the engine. 47 of those describe overheating, which makes it the most reported problem on the 2020 Blazer.

Tick what matches of 47 reports

23
15
12
1

What got replaced

Owners who name the part that was replaced mention the thermostat (40 reports) and the radiator (12 reports).

Recalls and investigations

No recall on the engine covers the 2020 model year as of Sep 19, 2026.

NHTSA investigations into the engine on the Blazer

EA94-029opened Jul 29, 1994
Engine And Engine Cooling · model years 1989 to 1993

Engine compartment fires. Closed jul 31, 1996.

NHTSA summary
AN ALLEGED MALFUNCTION IN THE ATLERNATOR RESULTING IN ENGINE COMPARTMET FIRES.

None of these investigations covers the 2020 model year.

What owners paid

10 of the 47 reports quote a price. Each dot is one quote. The middle half runs $800 to $3,500.

$800$1,400$3,500
$0k$2k$4k$6k$8k

When it happens

The middle half of failures fell between 49,663 and 63,000 miles, from the 17 reports that gave a mileage.

121
223
824
2125
1526

What owners wrote

“A/C quit working, "Caution Power steering assist ....working, temperature gauge reading zero ( far left side of gauge. PF62F Code set. Repair shop says very common. $800 To repair due to removal of plenum and other component including water temp sensor and thermostat while your there. $100+. 63k miles on vehicle.”

Filed Apr 24, 2026 · 63,000 miles

“2020 Blazer, 65,000 miles. Temp stuck on cold, A/C blows warm aor and driving assistance off. The radiator fan runs continuously. Check engine light on.”

Filed Apr 9, 2026 · 65,000 miles

“The thermostat failed on a trip locking in 0 temperature reading and steering assist warning. Licensed mechanic repaired on 10/9/25 invoice is available. 67,509 miles. This could risk overheating and destroying the engine and might cause accident. Two other friends have had similar issues, appears to be a safety defect!”

Filed Dec 22, 2025 · 67,509 miles

“Thermostat/thermostat sensor and complete water outlet system replacement at only 52,377 miles. The defective part was located under the Intake Manifold requiring its removal, excessive labor cost for the repair, and potential future engine issues due to exposed/open head gasket for the repair.”

Filed Dec 11, 2025 · 52,377 miles

Should you keep driving it?

This page can't tell you that. 0 of 47 reports involved a crash. Owners who file are the ones who had a bad experience, and nobody checks their reports. If the problem affects steering, braking, power or a fire risk, treat it as a safety fault and have it inspected before a long or high-speed drive.

File your own report with NHTSA. Complaint counts are how a problem gets an investigation.

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